In the rotary drilling of wells, and particularly in the rotary drilling of wells in offshore operations, there is a need for a casing handling system by which casing can be transported from the casing rack to a location where it is readily available to be run into the well bore, such as with an automatic pipe racker. Normally, in offshore operations rotary drilling is from drilling platforms or floating vessels, and, in many cases, the casing rack is located below deck although it can be located other places, such as on either side of the pipe racker, the other side of the derrick, in its own hold, or on deck, and it is necessary for the casing to be transported from the casing rack up to the upper deck adjacent the derrick floor for running into the well bore.
Patents which generally relate to casing handling systems include U.S. Pat. Nos. 2,900,091; 3,294,185; 3,420,318; 3,713,547; and 3,835,938. None of these patents, however, discloses or suggests the casing handling system of the present invention by which casing can be moved from the casing rack to a location for use in lowering into the well bore which can be accomplished easily and readily with a minimum of labor, time, swing motion and expense, and which restrains the casing from movement as a result of the dynamic motion of the vessel.